1. Field of the Invention
The present invention relates to a portable communication device and a system using the portable system that are utilized for achieving electric commerce using digital money. The present invention also relates to an attachment for a portable communication device which enables the portable communication device to be utilized for achieving electric commerce using digital money.
2. Description of the Related Art
As the Internet has become popular worldwide, movement of use of electric commerce utilizing the Internet has grown.
Conventionally, an electronic card is used for payment. A Mondex method is known in “(a) a home banking system using an IC card”. In this system, payment is done by an IC card, and deposit or transmittal of digital money can be done by using a home use telephone.
Additionally, an IC card having a portable telephone function is disclosed in Japanese Laid-Open Applications No. 8-153248 and No. 9-36972.
(b) Japanese Laid-Open Patent Application No. 8-153248 discloses an invention related to an automatic vending machine system using a deferred payment method using a portable telephone terminal, the title of the invention being “automatic vending machine system”.
(c) Japanese Laid-Open Patent Application No. 9-36972 discloses an invention related to a technique for adding a portable telephone function to an IC card, the title of the Invention being “complex IC card”.
Additionally, the following examples enable a digital information service by having a communication function of the portable telephone to process data other than a function such as a codec function necessary for communication.                (d) a combination of a notebook-type personal computer and a portable telephone        (e) a combination of an electronic diary or a personal digital assistant (PDA) and a portable telephone.        
However, in the usage of the above-mentioned cases (d) and (e), the portable telephone can be used only as a data communication means.
A description will now be given, with reference to FIG. 1, of a known PHS (personal handy-phone system) as a portable telephone having a data communication means.
The PHS shown in FIG. 1 comprises an antenna 1, a communication I/F 2, a modem 3, an audio codec DSP 4, a digital/analog converter 5, a microphone 6, a speaker 7, a liquid crystal display (LCD) 8, a key pad (KEY) 9, a light emitting diode (LED) 10, an external connector 11, a memory 12, a micro processing unit (MPU) 13, a protocol controller 14, a panel I/F 16. It should be noted that the audio codec DSP 4 and the digital/analog converter 5 together are referred to as a codec 15.
The communication I/F 2 controls the antenna 1 which receives radio frequency from a remote place and emits radio frequency to a remote place.
The modem 3 converts data to be transmitted into high-frequency signal and converts a received high-frequency signal into a base band signal.
The codec DSP 4 digitally processes a digital audio signal. The digital/analog converter 5 converts the audio signal into a digital audio signal, and the received digital audio signal into an analog audio signal.
The memory 12 stores data such as telephone number. FIG. 2 shows telephone number diary information stored in the memory 12.
The MPU 13 performs application programs such as a control program of a portable telephone or an address diary program.
The protocol controller 14 determines a data path. For example, the protocol controller 14 determines a data path so at to send data received by the antenna 1 to an external device via the external connector 11 or outputs the data to the speaker 7 via the codec 15.
The codec 15 converts the received digital audio signal into the analog audio signal so as to outputs the analog audio signal to the speaker 7, and converts an analog sound input to the microphone 6 into a digital audio signal.
When an audio signal is transmitted from the PHS to a remote telephone, the sound is detected by the microphone 6, and is transmitted to the remote telephone via the digital/analog converter 5, the audio codec DSP 4, the modem 3, the communication I/F 2 and the antenna 1.
Additionally, when data stored in the memory 12 is transmitted to a remote data communication terminal, the data is transmitted from the memory 12 to the remote data communication terminal via the MPU 13, the protocol controller 14, the modem 3, the communication I/F 2 and the antenna 1.
An audio signal transmitted by a remote telephone is received by the antenna 1, and a sound is generated by the speaker 7 via the communication I/F 2, the modem 3, the audio codec DSP 4 and the digital/analog converter 5.
Additionally, data transmitted by a remote data communication terminal is received by the antenna 1, and is output to an external device via the communication I/F 2, the modem 3, the protocol controller 14 and the external connector 11.
Accordingly, considering the PHS, in the above-mentioned modes of usage (d) and (e), data communication with an external notebook-type personal computer, an electronic diary or a PDA is merely achieved by the transfer of data via the portable communication I/F 2, the modem 3, the protocol controller 14 and the external connector 11.
There are following conventional cases that use a combination of portable communication devices.                (f) a combination of a GSM (global system for mobile communications) and a SIM (subscriber identity module card)        (g) a combination of a PDA and a keyboard        
The GSM in the case (f) is a portable telephone mainly used in European countries, and a card reader is incorporated in a main body which card reader is for reading a prepaid card referred to as a SIM card. Thereby, one can make a telephone call by borrowing a portable telephone owned by another person as if the portable telephone is a public telephone.
Additionally, in the case (g), as an example of a case in which a close contact type keyboard is attached to a PDA, there is a combination of a Palm Pilot manufactured by 3COM company and a single hand keyboard manufactured by Fujitsu Co, Ltd.
In the above-mentioned case (a) which is the “home banking system using an IC card”, a function of payment for purchase is provided, but money (digital cash) must be deposited in the electronic card (IC card) which is inconvenient for a user.
For example, in the home banking system using the Mondex method, a user must purchase a new telephone having an interface for an electronic card so as to deposit digital cash in the electronic card. Additionally, the user must purchase an exclusive attachment.
The electronic card is not provided with a function for communication by voice, and cannot accept an instruction by voice.
In the above-mentioned case (b) which is the invention disclosed in Japanese Laid-Open Patent Application No. 8-153248, payment for purchase is made by a deferred payment, and digital money cannot be used. Additionally, the invention disclosed in this patent document does not provide a communication function which is inconvenient for a user.
Additionally, in the deferred payment, if an amount of payment exceeds a payment capacity, there is no means for checking such a condition. Accordingly, a payment exceeding a payment capacity cannot be prevented.
In the above-mentioned case (c) which is the invention disclosed in Japanese Laid-Open Patent Application No. 9-36972, a technology of a complex IC card which combines the function of an IC card and the function of a portable telephone is disclosed. In this patent document, since an enciphering and deciphering function which necessary for handling digital money is not disclosed, the digital money cannot be used. Additionally, it is unclear how to use the digital money.
Accordingly, in order to use the digital money, the following issues are present.                (1) deposit and withdraw of the digital money must be easy.        (2) a support must be made such as a voice guidance in order to improve an operability.        (3) an immediate payment must be made within a deposit in a financial institution.        (4) A necessary security must be provided.        
The above-mentioned cases (d) and (e) and a handset of the PHS has a communication function but does not have a function to receive and pay money (digital cash). In order to receive and pay money, functions such as a data storing function, an enciphering function for communication or a selecting function to select data to be transmitted must be provided. However, conventional portable telephones do not have such functions.
Further, in order to achieve an information service system including a portable communication device which can be used by any one at any time and any place, portability must be important. Accordingly, such a portable telephone is required to be less than 1.5 times the conventional popular portable telephones with respect to its volume and weight. In this respect, the above-mentioned cases (d), (e) and (g) are insufficient for solving the above-mentioned issues. Particularly, the electronic diary and the PDA are provided with a display or a key panel, portability is deteriorated as compared to that of a purse. Additionally, a low cost is also one of the necessary elements. It is unacceptable if the price is more than a price of a portable telephone. The above-mentioned cases (d), (e) and (g) are insufficient to solve the above-mentioned issue.
Further, a data processor for receiving an information communication service and a memory for storing data are needed, and also a human I/F for interfacing between the service and an operator is needed. However, a device having only a memory provided in the above-mentioned case (f) is insufficient to cooperate with the human I/F.
Accordingly, the following issues are present in the data communication terminal.                (5) It must have a sufficiently small volume and weight so as to maintain portability.        (6) Both a communication function and an information processing function must be provided. (corresponding to the above-mentioned issue (2))        (7) A human I/F function such as a display function or a speaker function must be usable.        (8) It must be a low price.        